Check engine lite just came on. Had an issue with misfires

Customer Question

Check engine lite just came on. Had an issue with misfires in the past.JA: Does the light stay on, or does it blink?Customer: Stays on.JA: What is the make/model/year of your car?Customer: 1996 Bentley AzureJA: Are you fixing your Azure yourself? What have you tried so far?Customer: We'll see, probably not. It's been in and out of the shop for a variety of things.JA: Anything else you want the mechanic to know before I connect you?Customer: Error code is for multiple random misfires.

I'm assuming you're setting a P0300, multi cylinder misfire. This code sets when multiple cylinders are seen to be misfiring at the same time. There are several things that can cause misfiring ranging from inaccurate sensors, ignition system issues, fuel quality, possibly an exhaust restriction if you're having a lack of power, it could be low fuel pressure.

Lat year the problem was identified as a faulting air intake filter. Once this part was replaced, the light went off. I had one mechanic (Bentley Manhattan) tell me I needed an new ECU, which turned out to be false.The car is running fine. There may be a slight shudder when idling. It's tough to feel, but I thought I felt one yesterday.The light just went on after I had the car in the shop for power steering and break issues. I guess I will send it back in...